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Lower Lachlan wetlands

The Lachlan River is located within central western NSW and covers 85,532 square kilometres or 8% of the Murray-Darling system. The Lachlan has a large number of wetlands of national significance listed in A Directory of Important Wetlands in Australia, most notably Booligal Wetlands and the Great Cumbung Swamp. There are currently no Ramsar-listed wetlands in the Lachlan River system. Lachlan wetlands have been affected by irrigation development, flow regulation and floodplain development over a number of decades.

RERP action

Purchase of water access licences

RERP purchased 24,569 megalitres (ML) of general security and 1,000 ML of high security water access entitlements. Combined with the Australian Government’s environmental water holdings a total of 107,278 ML of general security and 1,733 ML of high security is available to the environment in addition to environmental water available under the Lachlan Water Sharing Plan. These licenses significantly improve the ability of government to supply environmental water to core wetlands and extend the scope of water allocated under the water sharing plan.

Adding Booligal Station and Geramy to the national reserve system

In April 2009, RERP funded the purchase of the property Booligal Station, which secured the protection of 2574 hectares of the upstream portion of Booligal Wetlands. The Booligal Wetlands are listed on the Register of the National Estate and in A Directory of Important Wetlands in Australia. The wetlands include one of the country’s five major breeding sites for the straw-necked ibis during flood events and the largest breeding population of glossy ibis documented in Australia. The riverine and wetland ecosystems on Booligal Station are significantly under-represented in the national reserve system and continue to be threatened by agricultural development.

RERP also funded the strategic purchase of a 1463 hectare section of the property Geramy in July 2009, securing 500 hectares of Lachlan Swamp. The purchase secures the flow pathway for the delivery of environmental water to the adjacent Kalyarr State Conservation Area, which contains the 1214-hectare Lake Ita. Lake Ita supports significant cultural and natural values, including river red gum and black box communities and crucial wetland habitats that are under-represented in the national reserve system.

Improved grazing on Willandra Creek

The landholder of Lignum Park along Willandra Creek has received incentive funding to protect 856 hectares of creek line and floodplain wetlands on the property. A 25 km fence has been built to enable the controlled grazing of high conservation value wetlands. A 10-year management agreement was negotiated between the landholder and the Office of Environment and Heritage, outlining respective obligations in support of the area’s wetland values.

Muggabah and Merrimajeel Regulators

The completion of the RERP-funded $1 million Muggabah and Merrimajeel regulators will re-establish more natural, intermittent flows in these creek systems (including Booligal Wetlands) and improve the efficiency of delivery of both environmental flows and domestic and stock replenishment flows. The regulators will:

• ensure water intended for Booligal Wetlands or Murrumbidgil Swamp on Merrimajeel Creek is not diverted to the Muggabah Creek system; and
• prevent un-seasonal flows entering these creek systems and assist in controlling vegetation chokes which impede the penetration of flows to the middle and lower reaches of the creeks.

Fostering Aboriginal connection to wetlands

A RERP-funded archaeological survey was conducted on a number of properties south of Booligal along the Lachlan River. The survey, involving members of the Hay Aboriginal community, identified and recorded over 400 previously unrecorded archaeological sites in the survey area. Sites included burials grounds, cooking mounds, mussell shell middens, modified (scarred) trees, stone tool artefacts and areas where native bush foods and medicines were gathered.

Community engagement activities

RERP has held several community events in the Lachlan Catchment, including a field day in Hillston in October 2009 to discuss ‘biodiversity in the bush’. Landholders, community members and agency staff participated in discussions about improved wetland management. Discussion included bird and water bug identification, the connection of Aboriginal people to local wetlands, as well as examples of traditional use of local plant species including basket weaving.

Lake Brewster Weir fish passage restoration

Lake Brewster Weir has been identified as the main barrier to fish passage in the Lachlan Catchment, under all flow conditions. Local species, including several threatened species such as silver perch and Murray cod, that require migration to complete their life cycle are negatively affected.

RERP funded the development of designs for the construction of a new fishway at Lake Brewster Weir, complimenting the recent installation of fishways at Bumbuggan, Island Creek and Lake Cargelligo Weir (currently under construction by State Water). On its completion, a Lake Brewster Weir fishway would open up approximately 235 km of river to fish passage.

Research to better understand complex wetland ecosystems

A number of research projects have been completed to improve the use of environmental water and underpin the development of models and decision support tools to improve the management of environmental flows for Lachlan wetlands:

• inundation maps were developed by analysing 18 years of remote sensing imagery which were used for input into ecosystem response models
• the relationship of flood frequency to vegetation community distribution was determined for the Great Cumbung Swamp and digital maps of vegetation extent and health were completed
• preliminary seed bank studies have indicated the viability of the seed bank in the bed of Lake Ita, suggesting its potential to regenerate flowing flooding
• a detailed description of the ecological character of the lower reaches of the Lachlan Floodplain has been completed and provides an understanding of the key ecological components and processes and the natural variability of the system.